Abstract: There is provided a method of forming a silicon dioxide film, which comprises repeating a step of depositing a silicon layer on a silicon substrate to form a silicon dioxide film of a predetermined thickness, and which makes it possible to suitably select the surface roughness of the silicon dioxide film that is formed and the rate of growth of the silicon film that is deposited. According to the method of forming the silicon dioxide film that is proposed above, it comprises a step of depositing any one of polysilicon, epitaxial silicon or amorphous silicon on the silicon substrate or on the silicon dioxide film formed on the silicon substrate by the thermal oxidation treatment to form a silicon film, and a step of thermally oxidizing the silicon film to convert it into a silicon dioxide film, the step of deposition and the step of thermal oxidation being repeated a plural number of times.